Pharmaceutical Manufacturing Handbook: Production and

112 STERILE PRODUCT MANUFACTURING
consistent effi cacy. The doors at each end can be automatically interlocked or
managed by standard operating procedure. In some instances a demarcation line is
used to delineate the extent to which individuals from one side should access the
air lock. It is good practice to carefully control and to minimize the time that any
operator spends accessing an air lock, therefore transfer of materials should be
carefully planned to minimize frequent and spontaneous access. Additionally, the
capacity of the air lock should be carefully considered relative to the actual production
requirements. Air locks that lack suffi cient capacity and that cannot provide
suffi cient air exchange will be less suited to the control of contamination into more
critical areas of the aseptic processing environment.
A smaller scale system with comparable capabilities is the pass - through. This
differs from the air lock primarily in dimension, as items are typically placed into the
pass - through by personnel, whereas the air lock is customary for pallet, portable
tanks, and larger items that are either rolled or mechanically lifted into position.
The operation of the pass - through can be either manual or automatic with similar
capabilities to that of the air lock described above. In general pass - throughs should
be supplied with HEPA fi lters and should be designed to meet the air quality level of
the higher air quality classifi cation room served. Pass - throughs should also be interlocked
and provide adequate facilities for decontamination of materials being
transferred.
Air locks and pass - throughs are bidirectional and can be used for movement in
either direction. When used as an exit route, the decontamination procedure can be
omitted. Where production volumes warrant separate entry and exit, air locks may
be necessary to maintain both adequate capacity and separation between clean and
used items. In an emergency, airlocks can serve as emergency exits for personnel, in
which case the interlocks can be overridden.
2.1.3.12 Gowning Rooms
The gowning area used for personnel entry/exit presents some unique problems.
Gowning facilities must be designed to the standards of the aseptic processing area,
yet personnel upon entry are certainly not gowned. Because ungowned staff will
release higher concentrations of contaminants into the environment, gown rooms
must be designed with suffi cient air exchange so that this contamination is effectively
and promptly removed. In general, the contamination load within a gowning
environment will require air exchange rates at the high end of recommended levels
for a given ISO 14644 air quality classifi cation. Gowning areas are separated into
well - defi ned zones where personnel can progress through the various stages of the
gowning process.
The most common approach in industry is a three - stage gowning area design in
which three linked rooms with increasing air quality levels are utilized to effi ciently
and safely affect clothing change. Staff should enter the fi rst state of the gowning
room wearing plant uniforms. No articles of outerwear worn outside the facility
should be worn to the gowning area. Therefore, a pregowning room equipped with
lockers is required so that operators can change into dedicated plant clothing prior
to moving to the gowning area. Generally, the pregowning locker area is not classifi
ed, although entry is controlled and temperature and humidity are maintained at
20 – 24 ° C and 50% ± 10%. The pregown area should have extensive hand - washing